Cheers all! I've been following this thread with great interest for some time. After a month+ of rain and scraping the ice off my windshield here in 'warm, sunny Florida' in the U.S., I decided the only way I'm going to fulfill my astronomy interests for the foreseeable future is to butcher a camera. I have a stock 6D, a 60D with a full spectrum mod pending and a 40D that was modded with a Baader filter some years ago. Soooooo I decided it's time to attempt Bayer filter removal on the 40D. Just ordered a spare sensor ($40US) because I looked askance at the gold wires on the original and scared the hell out of one, so it broke. I've no hope of fixing that, but it gives me a test subject for Bayer removal, and $40 is a fair price for admission. Cover glass came off the sensor rather easily with a gentle persuasion from a razor blade, gradually worked two corners and the side between them loose, used a toothpick to dribble some acetone at the edge of the cover glass, it wicked under the glass and shortly after that the whole thing just popped off. Neither plastic nor wooden tools helped much for microlens/Bayer removal, time to try a Dremel and polish. My goal is to get comfortable enough with this to try it on an XSi(450D) or maybe T2i(550D). I'd like to have one body that is more or less full resolution Ha/SII sensitive, the 6D and 60D do fine for visual/OIII. The camera disassembly / standard filter removal mod is relatively straightforward, rule #1 is keep the cat out of my work space. Ed Magowan